Due to modem failure and its replacement by comcast with an Arris tg862 modem/router, my unbutu server lost any functioality. All disks were scrambled and I reformated all disks and reinstalled ubuntu 12.04 server and other software (samba, webmin, etc). After installing the webmin program and trying to access webmin with the 10.0.0.10:10000 address from my IE9 browser page, i constantly get a certificate error. The warning page will not let go to the web site when I click - go to the web site anyway (NOT RECCOMMENED). I have set up webmin several times before and never had this happen.

The Arris modem/router uses addresses with a 10.0.0.1 instead of the traditional 192.168.1.1'

I've not seen this one before but all my googling about it suggests it's an IE problem and not a problem with your server. Are there any pending updates for your windows machine? Pending "Root Certificate" updates have been the solution to their problems. Hope they are with yours too?